Semiconductor devices are found in many products used in modern society. Semiconductors find applications in consumer items such as entertainment, communications, networks, computers, cellular phones, two-way pagers, laptop computers, personal digital assistants (PDAs), and music players. In the industrial or commercial market, semiconductors are found in military, aviation, automotive, industrial controllers, and office equipment.
The manufacture of semiconductor devices involves formation of a wafer having a plurality of die. Each die contains hundreds or thousands of transistors and other active and passive devices performing a variety of electrical functions. For a given wafer, each die from the wafer typically performs the same electrical function. Front-end manufacturing generally refers to formation of the semiconductor devices on the wafer. The finished wafer has an active side containing the transistors and other active and passive components. Back-end manufacturing refers to cutting or singulating the finished wafer into the individual die and then packaging the die for structural support and/or environmental isolation.
Some integrated circuit packages are hybrids containing radio frequency (RF) circuits and baseband circuits in a single package. Certain RF components, such as inductors, operate at very high frequencies and emit electromagnetic energy that can interfere with the operation of the baseband circuits, as well as other RF devices. To block or isolate the electromagnetic interference (EMI), the semiconductor packages found in the prior art have used shielding or insulating film in leaded or ball grid array (BGA) packages, such as found in U.S. Pat. Nos. 6,838,748, 7,125,744, and 7,187,060. However, these prior art designs typically provide only partial shielding, which limits the effectiveness of any EMI isolation.
Furthermore, with the growing demand for higher circuit integration, the space efficiencies and electrical and thermal performance of wafer level packages (WLP) and flip chip packages make these packages ever more popular. Yet, because of their unique layout and structure, there are few practical EMI solutions for hybrid WLP or flip chip packages.
A need exists for an effective EMI solution for WLP and flip chip packages containing RF and baseband circuits.